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BRIANNA KEILAR, CNN ANCHOR: Happening now, breaking news. Airport bombing. Two explosions and gunfire echo at Istanbul's Ataturk Airport. A Turkish official says two suspects blew themselves up at the airport's international terminal.

[17:00:26] Shots fired. Police fired at the suspects in an effort to stop them as passengers scrambled for cover.

And multiple casualties at this hour. Turkey's justice minister says that ten people have been killed in the attack. Emergency crews flooded the area. Security forces have sealed off the airport.

Wolf Blitzer is off today. I'm Brianna Keilar. Welcome to our viewers in the United States and around the world. You're in THE SITUATION ROOM.

And we have some breaking news. Suicide bombers attacking the international airport in Istanbul. Turkish officials say at least 10 people are dead, 60 wounded. That's the count at this point. There are new images that are coming in from the scene, and they show the chaos unfolding. We have correspondents around the world who are standing by, along with our analysts and our guests to bring full coverage of this breaking news story.

I want to go straight to CNN's Barbara Starr. She's at the Pentagon for us. What are you learning there, Barbara?

BARBARA STARR, CNN PENTAGON CORRESPONDENT: Good afternoon, Brianna.

President Obama was briefed on all of this just a short time ago by his homeland security and counterterrorism advisor, Lisa Monaco, bringing the White House up to date on what is happening.

Now security agencies across Washington and, I suspect, across Europe are scrambling, looking at the intelligence, trying to see what they may be able to learn about this. Typically they would reach out to Turkish security services, offer assistance, offer to share information and very quickly try to find out what the Turks may know.

There's no current claim of responsibility, and Turkey is a country that has been plagued with terrorist attacks, with ten people killed at this point and more than 60 injured at the world's 11th busiest airport, a major international hub. This is getting attention, of course, across the United States, Europe and NATO, Turkey being the only Muslim member of NATO. The Turks have had some attacks by ISIS, but they also have been

plagued with attacks by a Kurdish terrorist group called the PKK. They have been very active in Turkey. They have been trying to create mayhem across Turkey. There would be some considerable concern that this is a PKK attack. They are very antigovernment. The government very much wants to get after the PKK. But of course, we don't know at this hour.

What I can also tell you is right now the U.S. military doing a full head count across the U.S. Air Force in Turkey. There are U.S. Air Force troops there. Bases in southern Turkey. The U.S. European command also doing a head count.

Turkey, because it is a high terror threat country, has been discouraged by the State Department for civilians and military to travel on vacation there. But it is the height of the vacation season in Europe, so they are scrambling to figure out were there, possibly, any military personnel, U.S. military personnel at the airport tonight and just how many American civilians may also have been there -- Brianna.

KEILAR: All right. Barbara Starr, following the story from the Pentagon for us. Thank you so much.

Let's turn now to CNN senior international correspondent, Ivan Watson. He has spent years covering Turkey. He's been in and out of this airport hundreds of times, and he is live for us from Paris right now.

Ivan, you heard Barbara there talking about whether this could be Kurdish separatists or whether this could be ISIS. I think it's not lost on anyone that this happened at the international terminal of the international airport. And there's some saying that this may more fit the profile of an ISIS attack, even though we don't know at this point.

IVAN WATSON, CNN SENIOR INTERNATIONAL CORRESPONDENT: If you look at the past history of violence in Istanbul this year, there have been three major bombing attacks. One of them attributed to the Kurdish militant group targeted a police bus.

The other two, attributed to ISIS, targeted foreign tourists, pedestrians in different -- tourists -- concentrated areas of the city of more than 12 million people.

So judging by the past profile, it would make sense, more sense, perhaps, that ISIS would have carried out this attack. It is very early yet. This happened less than two hours ago, Brianna, and it appears to have targeted, according to Turkish government officials, the arrivals area just outside the entrance.

To get into the arrivals hall at Istanbul-Ataturk Airport, you have to go through security check point at the door there with police guards, security guards, X-rays, metal detectors, as well. And that is where government officials say either the police fired first or an attacker fired first, and then explosions ensued with a rising number of casualties. At least 10 dead and many more wounded.

[17:05:27] If it happened at that doorway, that is an area where you typically have dozens of yellow Turkish taxis waiting. And presumably, many of the victims could be not only relatives coming to greet loved ones, but also passengers arriving and also many taxi drivers who would normally be in that area of the airport.

Again Turkey dealing with a mounting terrorist war on two fronts, fighting ISIS on the one hand, which is very active across the border in Syria, and has been active in Turkey, as well. And fighting the Kurdistan workers' party, or PKK with a mounting number of deadly bombings being carried out by both groups in Istanbul and other major Turkish cities within the last year or two -- Brianna.

KEILAR: Ivan Watson for us in Paris. I want to bring in Clarissa Ward now as we're getting in some new video. She's joining me here in the studio. We have pictures coming to us now of the blast. And I think we're going to go ahead and show. Are we talking over those, or are we going to let that run?

CLARISSA WARD, CNN CORRESPONDENT: So I think what we should be seeing here, this is stunning video that we have just got in. And essentially, it's cell phone video that shows a computer, and on this computer you can see surveillance video that shows the moment of the blast. You see there the screen just lighting up as the blast goes off. You see people scattering.

This appears to be a cell-phone video recording of a computer that is showing surveillance video at the moments of the blast.

Now what's interesting, as well, if you look at the way these attacks were carried out, they do fit the profile. We can't say who's responsible, but they do fit the profile of ISIS, who are now not just using suicide bombers. They're using what they call inhumanity, which means suicide fighters. The idea is not just to blow yourself up. These men were reportedly carrying AK-47s, as well. The idea is to go in there to kill as many people as you possibly can with your AK, and then in the end, blow yourself up.

And you see there at the moment that entire airport is lit up by that massive blast which, of course, is believed to be one of the bombers detonating himself inside the airport terminal there.

KEILAR: So the vantage point is it clear, of this video, where this is coming from? Is this the outside area right outside of that initial security perimeter? Or do you think this is inside on the other side of it?

WARD: It appears to be inside on the other side of it. You heard Ivan say before, and it's important that our viewers understand that Istanbul airport is not like our airports. You have security immediately as you arrive at the airport. The glass doors open, and there is a large X-ray machine. And people wait in line.

KEILAR: Basically at the curb. WARD: Exactly. Yes, you have to put all of your bags and you

have to yourself go through an X-ray machine. Now, it's not clear, if they had Kalashnikovs, maybe they were able to sort of shoot their way through that and get into the terminal. There's still a lot of details we don't have yet. But this is the first images we're seeing of what appear to be the moment of the blast, Brianna.

KEILAR: All right, Clarissa. Thanks. And just stand by for us. I know you're going to be with us throughout this next couple hours. I do want to go now to an eyewitness. This is Laurence Cameron joining us on the phone. He is a witness who arrived at the airport as this chaos was unfolding.

Laurence, tell us what you saw.

LAURENCE CAMERON, WITNESS AT ISTANBUL AIRPORT (via phone): Yes, I just -- I didn't actually hear the explosion. I'd just stepped off of the plane. And as I walked round the corner to where the visas are issued, there was just a massive crowd of screaming people. Just pure panic. People were falling over themselves. The poor chap in a wheelchair was just left.

So yes, then everyone just sort of rushed to the back of the building, and then people ran the other way; and no one really seemed to know what was going on.

But I've actually got -- I can actually see the blast scene now. They've actually let us out of the control area, and I'm standing out where you can pick up a taxi. There's just this huge -- I mean, it must have been a huge explosion. There's bits of roof hanging down. There's blood still on the floor. Police now and soldiers everywhere. But yes, this is -- looks like initial blast outside, a second one somewhere, because there's a lot of damage inside the -- you know, the duty-free on the luggage -- the luggage carousel. That's what I'm seeing right now.

[17:10:08] KEILAR: So Laurence, you're looking at this right now as we speak, this scene of the attack.

CAMERON: Yes.

KEILAR: And you're seeing -- so you're near the duty-free. You're near the luggage carousel, and you're seeing...

CAMERON: No, no, no. I'm on the other side. We walk through the duty free, past the luggage carousels. And there was damage, you know, tiles and the roof on the floor. And then on the road where you normally hail a taxi, that's where the attack happened. And the ground is just sort of shredded and the roots shredded and the blast smashed. I'm just looking at there's maybe five or six ambulances, sort of (ph) everywhere, and bloodstain, tissues on the floor still. And I'm just getting moved on by police, but yes, it's quite a scene here.

KEILAR: What -- and what are authorities there telling you, Laurence, as you were -- as you're making your way through the airport and obviously trying to leave?

CAMERON: I mean, no authorities or anything else. I don't speak Turkish. No one really knows what's going on. I'm actually carrying two cameras, so I've posing as sort of a journalist so I can get a bit closer to see, but no. No one really seems to know what the situation is, apart from, obviously, two huge explosions that have all sorts of damage.

I'm getting moved on again away from the blast area.

KEILAR: You are getting...

CAMERON: It might be the last that I can see of it, in terms of from this standpoint here. Yes.

KEILAR: All right, Laurence.

CAMERON: I'm being put off the plane (ph).

KEILAR: Can you stand by? Can you stand by for us...

CAMERON: Yes.

KEILAR: ... as you're moving away from the blast scene. We're going to want to come back to you.

I want to get now to Ivan Watson, though, because there is an update on the death toll. What are you learning, Ivan?

WATSON: Brianna, the Istanbul governor has now raised the death toll in this deadly incident. Now 28 killed, according to the Istanbul governor, and some 60 wounded. At least 28 killed and 60 wounded now. Those figures coming in a little bit less than two hours since the government says that this attack took place, again, at the entrance to the arrivals hall at Istanbul-Ataturk Airport.

Sadly, this is not the deadliest bombing attack that Turkey has seen this year. There have been several deadlier attacks that have taken place in the capital, Ankara, when what are believed to have been Kurdish militants attacked security forces in buses in the capital there. There have been similar attacks on security forces in Istanbul, as well; as well as what are believed to have been ISIS suicide bomb attacks in Istanbul against foreign tourists in some of the more popular destinations of Istanbul's commercial capital.

But again, the death toll now in a little bit less than two hours since this incident is believed to have taken place, at least 28 killed, according to Istanbul's governor, at least 60 people wounded. And of course, the airport now very much shut down, not accepting flights.

KEILAR: All right, Ivan. Ivan Watson, stand by for us.

Just to recap what we're seeing here, these are pictures that are coming in to us from the scene of Ataturk Airport in Istanbul as the chaos unfolded after this -- what appears to be a double suicide attack there at the international terminal. You see an ambulance there. We know now that dozens of ambulances were mobilized to the airport. And the death toll has just changed; it's dramatically increased to 28 dead, 60 who are injured at this point in time.

Clarissa Ward, who has gone through this airport dozens and dozens of times, this is a transfer point between Europe and Asia. We will have many viewers who will have gone through this airport. You just heard from the eyewitness, you heard from Ivan. Are you expecting, perhaps, the death toll could continue to climb?

WARD: I think often in these situations, the death toll does keep going up and up as people who eventually succumb to their injuries. And you heard what Ivan said. This isn't even the deadliest attack this year in Turkey.

But what it is, is a reminder that they are trying to hit at the economy, at the tourism, at the symbolism, as well. This is an airport that connects east to west. Many, many people have traveled through this airport. Istanbul is an incredibly cosmopolitan city. People go there for the weekend. People go there to travel through to get to other destinations. It's one of the more crowded airports you will ever visit, and it's crowded -- can I just add, Brianna -- 24 hours a day, whether it's late at night, the middle of the night, early in the morning. They were even planning to try to expand the airport because of the density of travelers.

So one thing I can say about Istanbul-Ataturk Airport: no matter what time you go there, it is always very, very crowded. And it is crowded with an incredibly rich, eclectic international group of people from all over the world. There are very few nationalities who do not travel through Istanbul at some point when they're traveling from the east to the west.

KEILAR: It's an attack that puts so much fear into the hearts of so many people, as you mentioned. Not just the Turkish people, but so many folks from different countries who are traveling through there, and also the economy. The 11th busiest airport in the world, is that right?

WARD: Exactly, and that is what they were trying to do, whoever was responsible for this, whether it was a Kurdish separatist group, whether it was ISIS, whether it was some unknown group. They are trying to hit Istanbul's economy, Turkey's economy, destroy the tourism, destroy Istanbul as a hub, and you know, they're enjoying some success at doing it. It's a terrible thing.

KEILAR: All right, Clarissa. Thank you.

U.S. officials, of course, very concerned about what is happening there in Turkey. And we know that the president has been briefed. He is monitoring this situation.

Bri. And also trying to account for all American personnel in Istanbul. I understand the U.S. consulate in Istanbul is doing phone trees right now, scrambling to account for all of its personnel. The don't know if some of them could have been at the airport, either traveling or welcoming some friends and relatives at the airport.

They're also sending consular officers to the airport to see about any American victims. You know, you remember in Brussels, when it was so slow to find out about the nationalities of so many of the victims. They're hoping the Turks have a little bit more of an orderly process, and it will go a lot sooner.

There has been a lot of concern, Brianna, about this airport, about a potential attack on the airport for some time. There's been a long-standing travel warning against Turkey. But just this week, the U.S. issued a new travel warning particularly for the area of southeastern Turkey on the border with Syria, warning Americans not to travel there and noting that U.S. officials are forbidden from leaving, really, the consulate area to travel throughout Southeastern Turkey. That's how much concern there is about that border area.

Now U.S. officials right now not leaning towards PKK or ISIS. They understand there's a threat by both. But there has been a frustration on the part of U.S. officials in recent months on what they call a double game (ph) by Turkey. Turkey is a very important member of the anti-ISIS coalition and has been working with the U.S. in terms of battling ISIS.

But at the same time, as they've been facing those attacks, even though some of the signs are pointing towards ISIS, Turkey has been very quick to blame the PKK in calling that their primary threat. Tonight, U.S. officials are saying if it is indeed ISIS, this could be a wake-up call for Turkey.

KEILAR: All right. Elise, thank you so much. Stand by as we're in this rolling coverage of these attacks at the international airport in Istanbul.

I want to go back to the scene of the attack. That's where we find Joe Duran. Joe, tell us where you are, and give us a sense of what you're seeing.

JOE DURAN, CNN CORRESPONDENT (VIA PHONE): Yes, I'm actually 500 meters from the tournament (ph), where the explosion took place, and we are now not allowed. There are, as you can hear, ambulances coming in and out. I have seen hundreds of ambulances in both directions.

It's total chaos here at the entrance. The police are not letting anybody in. There are riot (ph) police and a lot of very shocked and (UNINTELLIGIBLE) happening to be walking, just thousands of them down the street away from the terminal. Some of them telling us stories of what they saw and the horrors (ph).

KEILAR: And what are they saying? Have you spoken to any of those people who are flooding away from the airport? Have they told you what they saw?

DURAN: Well, as you can imagine that many of them are just walking away, trying to get away, not saying much. But just the look on their face is enough. They are in shock. And some of them actually bleeding.

KEILAR: And what kind of injuries were you seeing of these folks who were walking away from the airport?

DURAN: It's very noisy here, and it is difficult to hear you.

KEILAR: I was asking you what injuries were you seeing of the walking wounded there who are streaming away from the airport?

DURAN: There were a couple of them walking with bandages on their heads. And I asked them what happened, and they didn't want to speak, but they said they did not need an ambulance. And they were leaving the ambulances for the seriously injured, and they were just trying to get to their families. There were a lot, thousands of people here who obviously were expecting family members, many of them crying and trying to get in. The police are blocking everyone, including journalists from getting closer than 500 meters where we are standing. We are not allowed anywhere. And basically (UNINTELLIGIBLE) walking with their bags and carts away from the terminal, nonstop for the last hour.

KEILAR: All right. Joe, stand by for me. We're actually going to try to better that audio signal with you. But you're describing thousands of people streaming away from the terminal.

Joe has been seeing, really, the walking wounded, people who have bandages on their heads and are leaving the ambulances to those who are more seriously injured. The death count now at 28, 60 injured in this airport attack at Istanbul's Ataturk Airport.

Clarissa, I know that you're getting some new information.

WARD: That's right. We're hearing from TRT, which is essentially Turkish state television, now that there were three explosions.

KEILAR: Three.

WARD: Previously, we had heard that there were only two explosions. This is obviously a very fluid situation. Events are changing quickly. We're learning more all of the time. But it does now appear, according to Turkish state television, that there were three explosions. This apparently indicating, clearly, this was some kind of a coordinated attack. And I go back again to some...

KEILAR: Three attackers then, is that the expectation?

WARD: One would assume, but...

KEILAR; OK.

WARD: ... we're not in the business of making assumptions.

KEILAR: Sure.

WARD: And we'll wait until we confirm that. But certainly, it appears at least two attackers, three explosions, some type of a coordinated attack.

And I come back again to this idea, as well, what ISIS uses very much in these attacks is this idea not of a suicide bomber, but of a suicide fighter. Inkamazi (ph) it's called in Arabic. And essentially, the idea is you have your Kalashnikov or your AK-47. You go in. You kill as many people as you possibly can, and only then do you detonate your suicide vest.

This is similar to what we saw in the Paris attacks. I mean, as I said before at this stage, we don't know if ISIS was responsible. But there are just a couple of things to consider as possible motives as we're moving forward.

No. 1, it has been in the news today, as we know, that Turkey finalized a kind of peace deal, if you will, with Israel today. As we know, that is a possible motivator for a number of different Islamist terrorist groups.

And another possible motivation, if it was ISIS, is that Turkey has really been cracking down on ISIS now. And you heard that in Elise Labott's report, as well. They've been particularly tough sealing that border that ISIS relies on to move fighters and weapons back and forth from Turkey to Syria.

You talk to ISIS fighters on the ground, they will tell you that they believe they are in a state of war with Turkey. And even though the Turkish people are Muslims, they view them as apostates because they're a member of NATO and because they work so closely with the west. So a lot of possible motivations there.

KEILAR: And the strategy for maximum casualties that we're seeing here. If that is indeed, if it is ISIS that is responsible for this.

I want to bring in Evan Perez, joining us now on set. What are you hearing?

EVAN PEREZ, CNN JUSTICE CORRESPONDENT: Well, you know, at this point, U.S. officials are still struggling to get any information they can from their Turkish counterparts. I mean, it is so early after this. And as you can tell, from the chaos from our reporter, from Joe Duran...

KEILAR: It sounded like the scene had actually just been sealed off, and we heard from another eyewitness who had just come through the terminal that he was right by the blast area, and now they've been moved farther back.

PEREZ: Yes, they moved back. And, you know, one of the things that we saw after Brussels, there was this call for people to perhaps move the perimeters for these soft targets, these airport terminals outside the airport. Move it back to try to protect people inside the terminal.

Well, the problem that this creates, as you can see from the scene here, it appears that these explosions, or at least a couple of them happened outside the airport. This is a place where people get screened before they can go into the terminal. And that's now the point where you can attack and where you can get a large number of people congregating, trying to get into the screening point to be able to get inside the airport.

So what you do -- this is a reminder that what you do when you create new perimeters outside the airports, you're simply creating new places for these attackers to target. And that's what appears to have happened here, sadly.

KEILAR: You just seem to move the target in a way.

I want to bring in Michael Weiss. He's a CNN contributor. He's also a senior editor at "The Daily Beast."

Michael, you're watching all of these new images that are coming in here to CNN. What are your thoughts as you -- as this all unfolds?

MICHAEL WEISS, CNN CONTRIBUTOR: Well, this is obviously a terrible tragedy. I have to say, my gut tells me this was probably jihadist in nature. I don't think it was the PKK. I'm not ruling it out.

But let me put it this way. If this was the PKK, game over. That would be the stupidest thing that organization can do, given the U.S. reliance on its affiliate in Syria to essentially lead the war against ISIS.

All of the hallmarks of an ISIS-style terrorist attack are here. Three suicide bombers. As Clarissa was saying, this suicide fighter methodology of trying to take out as many people with an AK-47 before detonating.

[07:25:10] A source close to me who actually told me that Turkey was about to say that the death toll had risen before the governor of Istanbul formally came out and said it was now 28, also told me that Istanbul police are reporting -- again, this is unconfirmed -- that shouts of "Allahu Akbar" were heard before the detonations.

So it looks to me like it could be ISIS, probably is. And there are other motives here for why now. ISIS is about to lose Mindich (ph), which is one of the most important cities they control in Aleppo province. That town is completely encircled by Syrian democratic forces backed by the United States.

Of course, the Turkish-Israeli rapprochement, which took place this week, would be an immediate catalyst for a jihadist attack on Turkey.

And also, let's not forget: Turkey has been shelling ISIS positions in northern Syria for several months now. And ISIS considers Turkey to be just as much an apostate regime as they do all of the other so-called tyrannical Arab governments in the region. So they have every...

KEILAR: Michael, I'm so sorry to interrupt you.

WEISS: Sure.

KEILAR: I just -- I'm going to have you stand by. We'll be coming right back to you, but Clarissa has some new information. What are you hearing?

WARD: Well, Brianna, essentially we're hearing now we knew it was three explosions, and we are now able to confirm, as well, three explosions and three bombers. This according to Turkish state television.

So this was three men, three bombs, presumably also three automatic weapons which were used to kill as many people as possible before the bombers then detonated themselves.

We still don't have a firm grip on exactly where the explosions took place. We heard earlier that one took place outside of the international departures area, where of course, you do get a line of people who are waiting to be screened. We've heard a report that one of them was in the parking lot. We don't yet know where the third bombing was.

But certainly, this appears to be a coordinated attack with deadly effect, Brianna.

KEILAR: Does that tell you anything, the profile of an attack like this? Three suicide bombers, it appears, right? Does that tell you anything about it looking more like an ISIS attack than an attack by the PKK, these Kurdish separatists?

PEREZ: I don't think it does. I mean, I think -- you know, certainly those facts don't, but there's other facts, as Clarissa has talked about. And we were talking about the choice of the international terminal of the Istanbul airport. That is something that, chances are, if you're an attacker, you're going to hit, probably, westerners; you're going to hit people who are international travelers. You're going to hit, certainly, a symbol of Turkey as a European and Middle Eastern power.

And so those are the things that ISIS and jihadi groups certainly try to target. PKK tries to focus its attacks mostly on the Turkish security apparatus.

WARD: Exactly, on police, on soldiers, and also I don't think we've seen from these Kurdish separatist groups anything like these kinds of coordinated attacks, let alone an attack where you have these so-called suicide fighters, where the objective is not just to blow yourself up, but to kill as many people as you can before you do that.

Now having said that, I've got my phone here. I'm monitoring Amak (ph), which is one of the news agencies affiliated with ISIS. They haven't claimed responsibility yet, but I would be surprised if it was the PKK or any Kurdish separatist group.

KEILAR: All right. We're still trying to pin that down, as I know you guys are talking to your sources.

I want to bring in Tom Fuentes. And Tom, I just want to reset what we know at this point.

You are looking at pictures coming into CNN from just moments ago. These are ambulances at the Ataturk Airport in Istanbul, Turkey, where there has been coordinated attack of three suicide bombers, it appears. That is what our Clarissa Ward is now reporting.

The death toll has increased to 28 dead now, 60 injured in the airport attack, and we're continuing to monitor that.

Tom Fuentes, you're our law enforcement analyst. I know that you bring a different perspective to this, certainly from the American law enforcement view. What are you -- what is really striking you as you see what is happening there in Istanbul?

TOM FUENTES, CNN LAW ENFORCEMENT ANALYST: I think what strikes me is that this airport has a lot better and more extensive security than probably any U.S. airport. So if this can happen there, you know, think what can happen here.

They do have -- I've flown through there many times. You can get off of a connecting flight, and connect to the gate next door and have to go through security all over again. So this is something that we don't see in our airports here to any of the extent.

But outside of any secure perimeter is the soft area. Whether its where passengers arrive and get picked up outside of baggage, or whether they get dropped off to go in the airport.

And another factor that U.S. airports, many of which have to deal with, is weather. You know, these airports in the Middle East have a lot more moderate temperatures. They don't face 20 below zero conditions in the middle of January like we would, where we don't want hundreds of people down on the sidewalk, elderly people with little children.

[17:30:23] So we have a lot more people traveling under a lot more diverse weather circumstances and other conditions that make it very difficult and more challenging for security at U.S. airports.

KEILAR: And I want to get now to Rene Marsh. Tom Fuentes, stand by for me.

Rene, I know that you're following the aviation situation right now. There is a ground stop, is that right? What can you tell us?

RENE MARSH, CNN AVIATION CORRESPONDENT: That's right, Brianna. At this hour, FAA just telling me that they've halted all U.S. flights to and from the airport there in Istanbul. Unclear when that will change, but of course, this is all in response to the explosions that happened there at that airport.

The FAA will do this, and they are doing this sort of thing to ensure safety of passengers. They do this from time to time when there is instability security-wise. And that's what we're seeing playing out here today.

Again, all flights to and from the U.S. between the U.S., I should say, and Istanbul, have been halted. And that is at the call of the FAA.

I can tell you that there are many direct flights between Istanbul and the United States, several cities within the United States. Most of those, or the majority of those are international carriers. There are no U.S. carriers that fly directly between the two.

But I will tell you, because there are those direct flights, security is an issue that the Department of Homeland Security pays close attention to. That sort of airport with direct flights to the United States, they're called last point of departure airports. And those sort of airports have to have very specific security measures in place. But of course, that all relates mostly to vetting of their airport workers, as well as the airport security checkpoint.

But what we're discussing here, again, it appears to be that soft target. So outside of what DHS would be overseeing at that security checkpoint.

But the headline for you, Brianna: anyone who has a direct flight to or from Istanbul from the United States will not be hopping on that flight, because the FAA has just made the call to halt all flights. And we do not know how long that will be in place.

KEILAR: Do you have any sense, are officials in the U.S. yet addressing whether there is any threat to the homeland here?

MARSH: We -- I just got off of the phone with DHS, and they are telling us that Secretary Johnson is aware of the situation. They're clearly monitoring all of this, but at this point, the stance still remains that there is no known threat to the homeland. At least, that is coming from the Department of Homeland Security.

But at this point, Brianna, still not many details, as you all have been discussing, who is to blame here.

KEILAR: All right, Rene, stay with us as we'll come back to you to see how this is affecting folks here in the U.S. with travel. This is a huge hub, certainly, that many people, Americans, Europeans, people moving from Asia and to the Middle East. This is a hub, the 11th busiest airport in the world, Ataturk Airport in Istanbul, Turkey, with 28 dead in this coordinated series of suicide bombings.

We just learned it's now up to three suicide bombings. We initially had thought that it was two. We now understand that it is three. We're going to be giving you more context on the location of this and exactly what officials are dealing with there on the ground, as you see ambulances coming in, in these new pictures coming in to CNN. We'll be right back.

(COMMERCIAL BREAK)

[17:39:24] KEILAR: We are following breaking news. At least 28 people are dead. Many more are wounded, the count now at almost 70. And this is coming after not just a pair of explosions, as we originally thought, but three explosions at the Ataturk Airport in Istanbul, Turkey. Three coordinated explosions. It appears to be three suicide bombers there at this massive transit hub of an airport in Istanbul.

I want to get more details now from journalist Andrew Finkel. He's joining us on the phone. Andrew, what are you learning?

ANDREW FINKEL, JOURNALIST (via phone): Well, as you say, the more we know, the worse the incident appears to have become. What the Turkey authorities appear to have been successful in doing is stopping these people from actually getting inside the terminal building. So most of the -- the incidents appear to have happened on the periphery: on the entrance, the road into the airport, outside the terminal, in the metro station beneath the terminal building.

But despite that, there appear to have been a large number of casualties that, as you say, the number originally was put at ten. Now it seems to have gone up to 28.

The authorities are busy evacuating the airport. I suppose there's fear that possibly there's another attack on the way, or there might be a bomb somewhere. So they're clearing this airport. And of course, that's an extraordinarily large task, because as you also said, Istanbul is a huge international hub. Many of the passengers there never actually go into the city. They're on their way from who knows, Cape Town to San Francisco, and they use Istanbul as a transit point. So there's a large number of passengers always in that airport, day and night, and evacuating that building is going to be a really serious task.

KEILAR: And Andrew, we now Istanbul is no stranger to attacks, especially recently. We've seen an uptick since 2014, both from Kurdish separatists and from ISIS here in recent years. But is there something about an attack like this, of this size, right there at the periphery of the airport, that tells us anything about how ISIS may be -- or if it is ISIS, how certainly some of the tactics may be changing here?

FINKEL: Well, they seem to have upped their game. As you say, there are two usual suspects in these sorts of incidents. There's the Kurdish separatist group, the PKK, but they tend to target sort of security forces. ISIS has in recent times gone after soft civilian targets. Tourists or in one terrible incident in Ankara last year they bombed a peace rally, and 100 people died in that. It was a horrendous incident.

But here, you have the sort of -- possibly the classic style of having various, not just one attacker, but more than -- but three in this case, trying to cause the maximum confusion, the maximum panic. They -- this is clearly a much more coordinated, more determined attack than what we've seen in the past, which has been sort of opportunistic attacks against groups of tourists in the city.

KEILAR: All right. Journalist Andrew Finkel, stay with us in case we can come back to you on this.

I do want to bring in Richard Quest. And Richard, we are looking at pictures coming into us from the Ataturk Airport in Istanbul. We're seeing people who are wounded sitting on the side. We see -- we see in this shot, a police officer who has blood on him. It does not appear that he is wounded. Obviously, all authorities rushing to help whoever they can as dozens and dozens of ambulances rush to the scene.

This is an airport. I know that you've been through this airport, and you really can't overstate how important this is in travel between Asia and Europe.

RICHARD QUEST, CNN AVIATION CORRESPONDENT: Absolutely, because not only is Turkey itself and Istanbul, I mean, the very bridge across the Bosphorus is Eurasia, the link between Europe and Asia. And Turkish Airlines, for whom this is the home and headquarters, has built its entire business on this idea of being a carrier, where they fly people in, people transfer, and they fly them out again. And it has been enormously successful at doing so.

However, of course, with the rise of militants and fanaticism and terrorism, so they have recognized the very serious potential risk of such attacks, and that's why Ataturk does have a security perimeter that is quite fierce and strong.

For instance, merely getting into the terminal building requires you to show identification, a ticket, and have your baggage X-rayed. And what we're seeing tonight are very different from Brussels airport, where of course, the bombers were able to get into the departure terminal here. Here, I mean the death toll is still horrendous, but the bombs and the attack took place at the perimeter level, both to the airport itself and to the terminal building.

So this, to some extent, shows the enormous difficulty, these so- called, to use a horrible phrase that they talk in this language, soft targets, where you're constantly looking for the weakest point. People have to get into an airport if they're going to travel. And what the terrorists and the bombers do is look for the weakest link.

But you can't keep, Brianna, extending the perimeter ever further backwards. You have to do it to the point where you think that it is safest and where the least damage can be caused.

KEILAR: All right, Richard. Stay with us. We're in rolling coverage of our breaking news. This triple suicide bombing at the Ataturk Airport in Istanbul, a massive transportation hub. The death count now at 28. There are at least 60 who are injured in this airport attack. And these are pictures coming into CNN. We're getting them moment by moment, and we're showing them to you.

We're also trying to get a better sense of the location of this attack and also the layout of the airport where this happened. Brian Todd has been looking into this for us. Brian, what can you share with us?

BRIAN TODD, CNN CORRESPONDENT: Well, Brianna, now that we know three suicide bombs at least, 28 dead at least, we're going to be finding out in the coming hours exactly where in the airport, at the airport these blasts occurred.

This is the overall layout of the Ataturk Airport in Istanbul, but here is what will possibly inform us about where the attacks occurred. We just heard Richard and our other experts saying that, at the Ataturk International Airport, they have security checkpoints just at the entrances to the airport. And I'm told by security experts that sometimes they even check your...

BRIANNA KEILAR, CNN ANCHOR: Happening now, breaking news. Airport bombing. Two explosions and gunfire echo at Istanbul's Ataturk Airport. A Turkish official says two suspects blew themselves up at the airport's international terminal.>